1. Field of the Invention
The present invention relates to a method and an apparatus for controlling a vehicular defroster for operating and controlling an air-conditioning defroster for discharging air-conditioned air against a windshield glass, and an electric heat-operated defroster having a heating wire embedded in the windshield glass.
2. Description of the Related Art
In general, the vehicular defroster is provided with an air-conditioning defroster for performing defogging by discharging air-conditioned air against a windshield glass, and an electric heat-operated defroster for performing defogging by using a heating wire embedded in the windshield glass.
The air-conditioning defroster is generally operated by manipulating an outlet selector switch provided on an air-conditioner control panel so that the air outlet mode in the passenger's compartment is changed to the "DEF" mode or the "FOOT/DEF" mode. On the other hand, the electric heat-operated defroster includes an exclusive on/off selector switch which is individually designed separately from the air-conditioning system.
However, the conventional vehicular defroster as described above individually includes the two means, i.e., the air-conditioning defroster and the electric heat-operated defroster which have the identical function to perform defogging for the windshield glass in order to ensure the frontward view from the passenger's compartment. Therefore, the passenger selectively operates the air-conditioning defroster and the electric heat-operated defroster. As a result, the operation to perform "defogging" is considerably complicated.
It is premised in the conventional vehicular defroster that the electric heat-operated defroster provided in the windshield glass is used when the ambient air temperature is relatively low, because of the following reason. That is, if the electric heat-operated defroster is operated at a temperature not less than a certain temperature, the windshield glass is distorted, or the windshield glass tends to be broken. Therefore, a problem is pointed out that it is complicated to manage the operation of the electric heat-operated defroster.